Abstract: A method of sensing a fluid. The method includes determining a slope based on a first measurement of a first ultrasonic pulse traveling through the fluid, a second measurement based on a second ultrasonic pulse traveling through the fluid, a first temperature of the fluid, and a second temperature of the fluid. The method further includes comparing the slope to a predetermined slope and the first measurement to a predetermined measurement.

Abstract: A system for sensing characteristics of a fluid contained within a tank. The system including an ultrasonic sensor, a temperature sensor, and a controller. The ultrasonic sensor is configured to output a ultrasonic pulse into the fluid, receive an echo of the ultrasonic pulse, and output a signal based on the received echo. The temperature sensor is configured to sense a temperature of the fluid and output a temperature signal corresponding to the temperature of the fluid. The controller is configured to determine a time-of-flight based on the output of the ultrasonic pulse and the received echo of the ultrasonic pulse, receive the temperature signal, determine a characteristic of the fluid based on the time-of-flight and the temperature signal, compare the characteristic of the fluid to a baseline characteristic, and output a signal based on the comparison between the characteristic of the fluid and the baseline characteristic.

Abstract: A method of sensing a fluid. The method includes determining a slope based on a first measurement of a first ultrasonic pulse traveling through the fluid, a second measurement based on a second ultrasonic pulse traveling through the fluid, a first temperature of the fluid, and a second temperature of the fluid. The method further includes comparing the slope to a predetermined slope and the first measurement to a predetermined measurement.

Abstract: A system for sensing characteristics of a fluid contained within a tank. The system including an ultrasonic sensor, a temperature sensor, and a controller. The ultrasonic sensor is configured to output a ultrasonic pulse into the fluid, receive an echo of the ultrasonic pulse, and output a signal based on the received echo. The temperature sensor is configured to sense a temperature of the fluid and output a temperature signal corresponding to the temperature of the fluid. The controller is configured to determine a time-of-flight based on the output of the ultrasonic pulse and the received echo of the ultrasonic pulse, receive the temperature signal, determine a characteristic of the fluid based on the time-of-flight and the temperature signal, compare the characteristic of the fluid to a baseline characteristic, and output a signal based on the comparison between the characteristic of the fluid and the baseline characteristic.

Abstract: A differential pressure sensor (10) having a housing 12 and a metal or alloy isolator (14) for stress isolation of a sensing cell (28) that is mounted to the isolator (14). The metal or alloy isolator (14) has an opening (16) therein for providing access to the sensing cell (28). The housing (12) is molded around the isolator (14) creating a seal therebetween and isolating the sensing cell (28).